Originally Posted By Bill Lewis
I just don't get where those perfect drum backing tracks come from and I hear registrations change but see no movement by the player.


If you watch the preset buttons you'll see them change. In this case he apparently sequenced a drum track but also added registration changes and programmed it so that the presets jump and skip around to the desired setting.

Another way to do it is to use kick switches on the expression pedal to change registrations, but that was not used in this video.